NCHREM

Technische Universiteit Delft - Netherlands

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The "National Centre for High Resolution Electron Microscopy" (NCHREM) at the Delft University of Technology is part of the Quantum Nanoscience department.

Three types of research projects are carried out at the NCHREM: detailed investigations of materials, method development, and service-related research. There is a strong focus on in-situ electron microscopy. The facilities are used by about 50 research groups (Netherlands and Europe) outside the NCHREM for ~150 days per year on our microscopes, on subjects as multilayers and monolayers for electronic, magnetic or optical properties, phase transformations in multilayers or metals and alloys, oxidation of metals and alloys, catalysts and zeolites, carbon nanotubes, graphene, organic materials and many others.
The NCHRTEM is capable of investigating the atomic structure, the chemical composition, and the electronic structure on a local scale (0.09 – 0.2 nm). Specific methods developed in Delft are:

ELECTRON DIFFRACTION analysis using dynamical scattering to retrieve the atomic position within a unit cell with <1 pm accuracy. This can be done on areas in the specimen as small as 5 nm diameter. A recent example is: "Towards automatic alignment of a crystalline sample in an electron microscope along a zone axis" by J. Jansen, M. Otten, and H. W. Zandbergen, published in Ultramicroscopy 125 (2013) 59.

IN-SITU INVESTIGATIONS IN THE TEM, i.e. collecting high resolution images at video rate at high or low temperature, at high gas pressure in combination with elevated temperature, or under the influence of an electrical current. These techniques are made possible by home-made MEMS based specimen holders that are unique in the world.

Especially the MEMS made nanoreactors for combining an elevated temperature with a gas atmosphere up to several bars of pressure and maintaining a spatial resolution for lattice imaging opens a wide range of new experiments. An example of recent results is "In-situ TEM at 1-4 bar hydrogen pressure on hydrogen storage materials" by T. Yokosawa, T. Alan, G. Pandraud, T. R. de Kruijff, B. Dam, and H.W. Zandbergen, published in Ultramicroscopy 112 (2012) 47.
At present a number of ESTEEMs transnational access requests have been made that aim at using the in-situ gas nanoreactors. The first steps to load the specific specimens in the nanoreactor are in progress.

Local contact:

Henny Zandbergen - This email address is being protected from spambots. You need JavaScript enabled to view it.